1. Field of the Invention
This invention relates generally to operational amplifiers and, more particularly, to an operational amplifier output stage which is driven by a single ended gain stage.
2. Description of the Prior Art
Known operational amplifiers which include junction field-effect-transistors (JFET) in the output stage such as the MLF155 manufactured by Motorola Semiconductors comprise a differential first or input stage, a second differential NPN gain stage having an output which is taken from an NPN follower, and an output stage which is driven by the NPN follower. In the semiconductor industry, efforts are constantly being made to produce smaller, less complex circuits in order to produce simple and less expensive integrated circuit chips. In the case of operational amplifiers, the reduction in circuit complexity also results in the elimination of certain parasitic effects which degrade high frequency performance.